Sheet finishing apparatus of image forming apparatus

ABSTRACT

A sheet finishing apparatus includes a conveyance section to convey a recording medium supplied from an image forming section in a paper discharge direction, and a finishing section which protrudes to a conveyance path from a side, parallel to the paper discharge direction, of the conveyance path of the recording medium in the conveyance section and finishes the recording medium traveling along the conveyance path.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Provisional U.S. Applications 61/178420 filed on May 14, 2009 and 61/178421 filed on May 14, 2009, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

Embodiments described herein relates generally to a sheet finishing apparatus for finishing a sheet on which an image is formed.

BACKGROUND

There is a sheet finishing apparatus for performing finishing, such as stapling or punching, on a sheet on which an image is formed by an image forming apparatus. Hitherto, in the sheet finishing apparatus, a finishing section, such as a staple unit or a punch unit, is arranged at a rear end side perpendicular to a sheet discharge direction. In the sheet finishing apparatus as stated above, when the finishing section, such as the staple unit or the punch unit, is fixed in order to achieve miniaturization and reduction in cost, the staple unit can not staple plural portions, and there is a fear that the user's needs can not be sufficiently satisfied. Besides, in the punch unit, punch hole standards are different between Japan and overseas, plural kinds of punch units based on the respective standards must be provided, and there is a feat that mass productivity is reduced.

Thus, it is desired to develop a sheet finishing apparatus in which usability is not impaired and reduction in cost can be realized.

According to an embodiment, a sheet finishing apparatus includes a conveyance section to convey a recording medium supplied from an image forming section in a paper discharge direction, and a finishing section which protrudes to a conveyance path from a side, parallel to the paper discharge direction, of the conveyance path of the recording medium in the conveyance section and finishes the recording medium traveling along the conveyance path.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural view showing a sheet finishing apparatus connected to an MFP of a first embodiment;

FIG. 2 is a schematic structural view showing a finisher of the first embodiment;

FIG. 3 is a schematic explanatory view in which the finisher of the first embodiment is seen from the above of a conveyance path;

FIG. 4 is a schematic explanatory view showing the arrangement of a stapler of the first embodiment;

FIG. 5 is a schematic explanatory view showing a belt conveyance device of the first embodiment;

FIG. 6 is a schematic explanatory view showing a clip of the first embodiment;

FIG. 7 is a schematic explanatory view showing a state where the tip of the clip of the first embodiment is opened;

FIG. 8 is a block diagram showing a control system of the first embodiment;

FIG. 9 is a schematic structural view showing the stapler and an auxiliary alignment plate of the first embodiment;

FIG. 10 is a schematic structural view showing a finisher of a second embodiment;

FIG. 11 is a block diagram showing a control system of the second embodiment; and

FIG. 12 is a schematic structural view of the finisher of the second embodiment in which a stapler is arranged adjacently to a punch and which is seen from the above of a conveyance path.

DETAILED DESCRIPTION

According to an embodiment, a sheet finishing apparatus includes a conveyance section to convey a recording medium supplied from an image forming section in a paper discharge direction, and a finishing section which protrudes to a conveyance path from a side, parallel to the paper discharge direction, of the conveyance path of the recording medium in the conveyance section and finishes the recording medium traveling along the conveyance path.

Hereinafter, a first embodiment will be described. FIG. 1 is a schematic explanatory view showing a finisher 20 as a sheet finishing apparatus provided in an MFP 10 as an image forming section of the first embodiment. The finisher 20 is positioned in a hollow barrel 10 a formed in the MFP 10 and is connected to the MFP 10. The MFP 10 includes, for example, a scanner 8, a printer section 11, a control panel 14 and a paper feed section 16.

The MFP 10 forms an image on a sheet P as a recording medium by the printer section 11 in accordance with image data read by the scanner 8. The printer section 11 forms color toner images corresponding to the image data by, for example, respective stations 13Y, 13M, 13C and 13K of yellow (Y), magenta (M) , cyan (C) and black (K), and then forms the color toner images on a transfer belt 11 a. The printer section 11 transfers the color toner images on the transfer belt 11 a by a transfer section 11 b to the sheet P supplied from the paper feed section 16. The printer section 11 fixes the color toner images to the sheet P by a fixing section 11 c, and discharges the sheet P from a paper discharge roller pair 12.

As shown in FIG. 2 to FIG. 6, the finisher 20 includes a discharge tray 22 to support the sheet P supplied from the paper discharge roller pair 12. The finisher 20 includes a processing tray 21 which is disposed above a conveyance path to convey the sheet supplied from the paper discharge roller pair 12 to the discharge tray 22 and supports the sheet P. The finisher 20 includes an alignment roller unit 23 as an alignment section to align the sheet P on the processing tray 21, a belt conveyance device 24 as a conveyance section to convey the sheet P in a paper discharge direction of an arrow m direction, a longitudinal alignment plate 26, a staple unit 27 as a finishing section, and a sensor 35 to detect the traveling of the sheet P. The processing tray 21 includes a cut-out section 21 a at a rear side.

The alignment roller unit 23 includes an alignment roller 23 c at the tip of an arm 23 b rotating using a shaft 23 a as a fulcrum. The arm 23 b is rotated by ON-OFF operation of an arm solenoid 28. When the arm solenoid 28 is ON, the arm 23 b is moved to a position indicated by a dotted line in FIG. 2. The alignment roller 23 c is separated from the sheet P on the processing tray 21. When the arm solenoid 28 is OFF, the arm 23 b is moved by its own weight to a position indicated by a solid line in FIG. 2. The alignment roller 23 c contacts with the upper surface of the sheet P on the processing tray 21. A portion of the alignment roller 23 c, which contacts with the sheet P, is formed of an elastic tube 30.

A roller motor 38 rotates the alignment roller 23 c forwardly and reversely through a link gear 38 a, the shaft 23 a, a timing belt 38 b and a roller shaft 30 a. When conveying the sheet P in the arrow m direction, the alignment roller 23 c rotates in an arrow r direction of FIG. 2. When vertically aligning the sheet P, the alignment roller 23 c rotates in an arrow s direction. When laterally aligning the sheet P, the alignment roller 23 c stops the rotation.

The alignment roller unit 23 slides in a direction perpendicular to the arrow m direction. The arm 23 b of the alignment roller unit 23 slides along the shaft 23 a by sliding a rack 32 by a pinion gear 34 driven by a gear motor 33.

The longitudinal alignment plate 26 is positioned at the upstream side end of the processing tray 21 in the paper discharge direction. The longitudinal alignment plate 26 is perpendicular to the processing tray 21, contacts with a rear end Pr of the sheet P at the time of alignment, and aligns the sheet P in the longitudinal direction.

A stapler 27 a of the staple unit 27 is positioned at the cut-out section 21 a of the processing tray 21, and an opening section 27 b protrudes to the conveyance path of the sheet P. The height of an opening section bottom surface 27 c of the stapler 27 a is equal to that of the surface of the processing tray 21. An opening section side wall 27 d of the stapler 27 a is a lateral alignment reference of the sheet P. When the sheet P is aligned in the lateral direction on the processing tray 21, a lateral end Ps of the sheet P contacts with the opening section side wall 27 d and the sheet P is laterally aligned.

The finisher 20 includes a chuck 31 to prevent the sheet P after the alignment operation from shifting on the processing tray 21. The chuck 31 is opened and closed by ON-OFF operation of a solenoid 37, and when the solenoid 37 is ON, the chuck is opened as shown by a dotted line in FIG. 2, and when the solenoid 37 is OFF, the chuck is closed as indicated by a solid line in FIG. 2. The chuck 31 is opened when the sheet P is aligned on the processing tray 21, and is closed when the alignment operation of the sheet P is finished.

As shown in FIG. 4, the stapler 27 a staples the sheet P, which passes through the opening section 27 b, in the opening section 27 b protruding to the conveyance path of the sheet P. The staple unit 27 includes a staple motor 29 to rotate and move the stapler 27 a. When stapling is performed in parallel to the sheet P, the stapler 27 a is arranged so that the opening section side wall 27 d is parallel to the arrow m direction. When stapling is performed obliquely to the sheet P, the staple motor 29 rotates the stapler 27 a around a fulcrum 27 f in an arrow q direction by, for example, 45°.

The belt conveyance device 24 is positioned at substantially the center of the processing tray 21. As shown in FIG. 5, the belt conveyance device 24 includes a clip 24 b on a conveyance belt 24 a. The conveyance belt 24 a stretched between a driving roller 42 and a driven roller 43 rotates in an arrow n direction by driving the driving roller 42 by a stepping motor 25. The conveyance belt 24 a uses the clip 24 b to clip one or plural sheets P on the processing tray 21 and conveys them in a direction toward the discharge tray 22. When the stapler 27 a staples the sheet P, the belt conveyance device 24 temporarily stops the conveyance of the sheet P. After the stapling is finished, the conveyance belt device 24 restarts the conveyance of the sheet P.

The clip 24 b has a rotation force in an arrow t direction by a spring 24 c. The clip 24 b includes a cam 24 d at, for example, a side part on the front side. The belt conveyance device 24 includes a protruding cam follower 40 at the outer periphery of the conveyance belt 24 a on the driven roller 43 side. When the cam 24 d of the clip 24 b moves along the cam follower 40, as shown in FIG. 7, the clip 24 b rotates in an arrow x direction, and the tip of the clip 24 b is opened. When the clip 24 b reaches the rear end of the processing tray 21, the cam 24 d disengages from the cam follower 40, and rotates in the arrow t direction by the rotation force of the spring 24 c, and the clip 24 b is closed. The rear end Pr of the sheet P on the processing tray 21 is clipped between the clip 24 b and the conveyance belt 24 a. When the rear end Pr of the sheet P reaches the end on the driving roller 42 side, it disengages from the clip 24 b by the firmness (tightness) of the sheet P.

Next, a control system of the finisher 20 will be described. As shown in a block diagram of FIG. 8, a finisher control circuit 51 is connected to a finisher CPU 52. The finisher CPU 52 is connected to an MFP-CPU 53 to control the MFP 10. The finisher control circuit 51 controls the stapler 27 a, the stepping motor 25, the arm solenoid 28, the staple motor 29, the solenoid 37, the roller motor 38, the gear motor 33 and the like. The detection result of the sensor 35 is inputted to the finisher CPU 52. The MFP-CPU 53 inputs the number of times of stapling by the stapler 27 a, the staple position, the staple angle and the like to the finisher CPU 52 by the input from the control panel 14. A memory 53 a of the MFP-CPU 53 stores, for example, a program for driving the MFP 10 or the finisher 20.

When printing is started, the MFP 10 forms a color toner image on the sheet P, and then discharges the sheet P to the finisher 20 side. The finisher 20 receives the sheet P supplied from the MFP 10. While the sheet P is received, the alignment roller 23 c of the finisher 20 is separate from the processing tray 21.

(1) Case Where Finishing on the Sheet P is not Performed

When the sensor 35 detects that introduction of the sheet P onto the processing tray 21 is finished, the finisher control circuit 51 turns OFF the arm solenoid 28, and brings the alignment roller 23 c into contact with the sheet P. The finisher control circuit 51 forwardly rotates the roller motor 38, and rotates the alignment roller 23 c in the arrow r direction. The alignment roller 23 c conveys the sheet P in the arrow m direction, and discharges it to the discharge tray 22.

(2) Case Where a Bundle of Sheets P is Discharged as Finishing on the Sheet P

When the MFP-CPU 53 inputs an instruction of bundle discharge to the finisher CPU 52 from the control panel 14, the finisher control circuit 51 aligns plural sheets P, and then discharges the bundle. When the sensor 35 detects that introduction of the sheets P onto the processing tray 21 is finished, the finisher control circuit 51 turns ON the solenoid 37 to open the chuck 31, turns OFF the arm solenoid 28, and brings the alignment roller 23 c into contact with the first sheet P. The finisher control circuit 51 reversely rotates the roller motor 38 by a specified amount, and rotates the alignment roller 23 c in the arrow s direction. The alignment roller 23 c conveys the sheet P in the reverse direction to the arrow m direction, causes the rear end Pr of the sheet P to abut on the alignment plate 26, and longitudinally aligns the sheet P.

The finisher control circuit 51 forwardly rotates the gear motor 33, and slides the alignment roller unit 23 from A position to B position in an arrow v direction (where, both the A position and the B position are the position of the center of the roller shaft 30 a). During the slide movement, the alignment roller 23 c moves the sheet P by a friction force in the arrow v direction, causes the lateral end Ps of the sheet P to abut on the opening section side wall 27 d of the stapler 27 b, and laterally aligns the sheet P.

When the longitudinal alignment and the lateral alignment of the first sheet P are completed, the finisher control circuit 51 turns OFF the solenoid 37 to close the chuck 31 and prevents the sheet P from shifting. The finisher control circuit 51 turns ON the arm solenoid 28, and reversely rotates the gear motor 33. The alignment roller 23 c is separated from the sheet P, and the alignment roller unit 23 slides in an arrow w direction and returns from the B position to the A position.

The finisher control circuit 51 aligns the second or later sheet P on the processing tray 21 similarly to the first sheet. When the alignment of a specified number of sheets P is completed, the finisher control circuit 51 turns ON the stepping motor 25, and rotates the conveyance belt 24 a in the arrow n direction. The conveyance belt 24 a clips the rear end Pr of the plural aligned sheets P by the clip 24 b, conveys the bundle of sheets P in the arrow m direction, and discharges the bundle to the discharge tray 22. At the time of the bundle discharge, the lateral ends Ps of the plural sheets P travel in the opening section 27 b of the stapler 27 a.

(3) Case Where a Bundle of Aligned Sheets P is Stapled as Finishing of the Sheets P

When the MFP-CPU 53 inputs an instruction of stapling from the control panel 14 to the finisher CPU 52, the finisher control circuit 51 staples a bundle of sheets P traveling in the opening section 27 b of the stapler 27 a. While conveying the bundle of sheets P aligned in the above (2) by the conveyance belt 24 a in the arrow m direction, the finisher control circuit 51 temporarily stops the bundle of sheets P, staples it by the stapler 27 a, and then restarts the conveyance of the bundle of sheets P.

For example, when the needle of the stapler 27 a is stapled in parallel to the arrow m direction, after the sensor 35 detects the rear end Pr of the sheet P, the stepping motor 25 is temporarily stopped after being driven for a specified number of steps, and a desired staple position is stopped at the opening section 27 b of the stapler 27 a. After the stapling is finished, driving of the stepping motor 25 is restarted, and the bundle of stapled sheets P is discharged to the discharge tray 22. When stapling is performed at plural places of the bundle of sheets P, each time the desired staple position reaches the opening section 27 b of the stapler 27 a, (a) the bundle of sheets P is temporarily stopped, (b) stapling is performed and (c) the conveyance of the bundle of sheets P is restarted after the end of the stapling, and these processes (a) to (c) are repeated.

For example, when the needle of the stapler 27 a is inclined with respect to the arrow m direction, and the bundle of sheets P is stapled, the staple motor 29 rotates the stapler 27 a in the arrow q direction by 45°. However, at the time of rotation of the stapler 27 a, it is prevented that the opening section side wall 27 d of the stapler 27 a contacts with the bundle of sheets P. Thus, as indicated by a dotted line in FIG. 3, when the rear end Pr of the bundle of sheets P passes through the center D of the stapler 27 a, the stepping motor 25 immediately temporarily stops.

Next, the staple motor 29 rotates the stapler 27 a in the arrow q direction by 45°. The stapler 27 a obliquely staples the rear end Pr of the bundle of sheets P at the rear side. Thereafter, the stepping motor 25 restarts driving, and discharges the bundle of stapled sheets P to the discharge tray 22. After the stapling is finished, the staple motor 29 rotates the stapler 27 a in the reverse direction to the arrow q direction by 45°, and returns the opening section side wall 27 d of the stapler 27 a to be parallel to the arrow m direction.

As shown in FIG. 9, the stapler 27 a may be provided with auxiliary alignment plates 46 extending like a vane from both sides of the opening section side wall 27 d. By providing the auxiliary alignment plates 46, the lateral end Ps of the sheet P is made to abut on the opening section side wall 27 d, and the alignment property at the time of lateral alignment of the sheet P can be further improved.

According to the first embodiment, in the state where the stapler 27 a is arranged at the specified position of the side parallel to the traveling direction of the sheet P, the bundle of sheets P can be stapled in various forms desired by the user. Besides, the opening section 27 b of the stapler 27 a can be arranged to protrude onto the conveyance path of the sheet P. Accordingly, the miniaturization of the finisher 20 is realized, the staple in the form desired by the user is obtained, and the usability can be improved.

Next, a second embodiment will be described. The second embodiment is different from the first embodiment in that a punch unit is provided as a finishing section. In the second embodiment, the same component as the component described in the first embodiment is denoted by the same reference numeral, and its detailed description is omitted.

As shown in FIG. 10, a finisher 120 includes a punch 60 as a punch unit at a position of a cut-out section 21 a of a processing tray 21. An opening section 60 a of the punch 60 protrudes to a conveyance path of a sheet P. The height of an opening section bottom surface 60 b of the punch 60 is equal to that of a surface of the processing tray 21. An opening section side wall 60 c of the punch 60 is a lateral alignment reference of the sheet P. When the sheet P is aligned in a lateral direction on the processing tray 21, a lateral end Ps of the sheet P is brought into contact with the opening section side wall 60 c and the sheet P is laterally aligned. The lateral end Ps of the laterally aligned sheet P travels in the opening section 60 a of the punch 60.

As shown in a block diagram of FIG. 11, a finisher control circuit 151 is connected to a finisher CPU 152. The finisher CPU 152 is connected to an MFP-CPU 53 to control an MFP 10. The finisher control circuit 151 controls a stepping motor 25, an arm solenoid 28, a solenoid 37, a roller motor 38, a gear motor 33, the punch 60 and the like. The detection result of a sensor 35 is inputted to the finisher CPU 152. The MFP-CPU 53 inputs the number of times of punching of the punch 60, the punch position and the like to the finisher CPU 152 by an input from a control panel 14. A memory 53 a of the MFP-CPU 53 stores, for example, a program for driving the MFP 10 or the finisher 120, and punch hole standard data as user data of the MFP 10. For example, according to the user area (Japan, North America, Europe, etc.), there is a case where the size of the sheet P, or standards of the number of punch holes to the sheet P, the position of the punch hole, the interval between the punch holes, etc. are different. Even when the standards of the number of punch holes, the position of the punch hole, and the interval between the punch holes are different, the finisher 120 obtains the punch hole standard data stored in the memory 53 a, and the punch holes of the standards desired by the user are obtained at the time of punching.

(4) Case Where a Punch Hole is Provided in a Bundle of Aligned Sheets P as Finishing of the Sheets P

At the time of printing, the operator inputs, from the control panel 14, an instruction of sheet finishing to form a punch hole in the sheet P. The finisher CPU 152 instructs the finisher control circuit 151 based on the punch hole standard data stored in the memory 53 a of the MFP-CPU 53.

For example, based on the punch hole standard data for Japan, the finisher 120 forms two punch holes in a bundle of sheets P. While the finisher control circuit 151 conveys the bundle of sheets P aligned in the above (2) by a conveyance belt 24 a in an arrow m direction, (d) temporarily stops the bundle of sheets P at the first position in accordance with the punch hole standard data for Japan. (e) The punch 60 forms the first punch hole in the bundle of sheets P. (f) After the first punch hole is formed, the conveyance belt 24 a restarts the conveyance of the bundle of sheets P, conveys it by a specified distance, and again temporarily stops the bundle of sheets P at a second position in accordance with the punch hole standard data for Japan. (g) The punch 60 forms the second punch hole in the bundle of sheets P. (h) After the second punch hole is formed, the conveyance belt 24 a restarts the conveyance of the bundle of sheets P, and discharges the bundle of sheets P to a discharge tray 22.

Although the arrangement position of the punch 60 in the finisher 120 is arbitrary, for example, based on punch hole standard data for each area, the punch 60 can be previously arranged at the first punch hole position. When the punch 60 is arranged at the first punch hole position, in the finisher 120, after a bundle of sheets P is aligned, the first punch hole is first formed, and then, the conveyance of the bundle of sheets P is started. In the finisher 120, the processing time of punching can be shortened.

Irrespective of the punch hole standard data stored in the memory 53 a, the finisher CPU 152 can also instruct the finisher control circuit 151 to form a punch hole desired by the user in a bundle of sheets P in accordance with the input data from the control panel 14. Besides, even when the number of sheets P traveling in the opening section 60 a is one, the punch 60 can form a punch hole.

Besides, as shown in FIG. 12, in the finisher 120, a stapler 27 a may be arranged adjacently to the punch 60. The finisher 120 can perform finishing desired by the user, such as stapling or punching, on the sheet P traveling in an opening section 27 b of the stapler 27 a and the opening section 60 a of the punch 60. The arrangement of the stapler 27 a and the punch 60 is not limited as long as the rotation of the stapler 27 a is not blocked, and the stapler 27 a and the punch 60 may be set in a common case.

According to the second embodiment, it is not necessary that a punch unit different in shape is prepared for each user different in punch hole standards, and the punch unit is mounted in the finisher 120. Punch holes of various forms desired by the user can be formed in the sheet P in the state where the punch 60 is fixed to the specified position of the side parallel to the traveling direction of the sheet P, and the punch 60 can be made common. Besides, the punch 60 can be arranged to protrude onto the conveyance path of the sheet P. Accordingly, the miniaturization of the finisher 120 is realized, the mass productivity is improved, a punch hole according to the standards or shape desired by the user is obtained, and the usability can be improved.

While certain embodiments have been described these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel apparatus and methods described herein may be embodied in a variety of other forms: furthermore various omissions, substitutions and changes in the form o the apparatus and methods described herein may be made without departing from the spirit of the inventions. The accompanying claims and there equivalents are intended to cover such forms of modifications as would fall within the scope and spirit of the invention. 

1. A sheet finishing apparatus comprising: a conveyance section to convey a recording medium supplied from an image forming section in a paper discharge direction; and a finishing section which protrudes to a conveyance path from a side, parallel to the paper discharge direction, of the conveyance path of the recording medium in the conveyance section and finishes the recording medium traveling along the conveyance path.
 2. The apparatus of claim 1, wherein the finishing section is a staple unit to staple a plurality of the recording medium.
 3. The apparatus of claim 1, wherein the finishing section is a punch unit to form a hole in the recording medium.
 4. The apparatus of claim 1, wherein the finishing section is a staple unit to staple a plurality of the recording medium and a punch unit to form a hole in the recording medium.
 5. The apparatus of claim 1, wherein the conveyance section temporarily stops the traveling recording medium at a time of finishing in the finishing section.
 6. The apparatus of claim 1, wherein the finishing section finishes the traveling recording medium a plurality of numbers of times, and the conveyance section temporarily stops the traveling recording medium each time the finishing section finishes the medium.
 7. The apparatus of claim 2, wherein the staple unit can rotate a staple section, and when the recording medium is stapled obliquely to the paper discharge direction, the staple unit rotates the staple section after a rear end of the recording medium in the paper discharge direction passes through a center of an opening section of the staple section.
 8. The apparatus of claim 1, further comprising an alignment section which moves the recording medium in a direction perpendicular to the paper discharge direction and laterally aligns a side of the recording medium parallel to the paper discharge direction, and in which an opening section side wall of the finishing section is a lateral alignment reference surface of the recording medium.
 9. The apparatus of claim 3, wherein the punch unit sets a punch hole position and the number of punch holes on the recording medium based on user data.
 10. The apparatus of claim 1, wherein the conveyance section includes a conveyance belt and a clip which is disposed on the conveyance belt and clips the recording medium.
 11. A sheet finishing apparatus comprising: a conveyance section to convey a recording medium supplied from an image forming section in a paper discharge direction; and a finishing section which has an opening section inside of which the recording medium conveyed by the conveyance section can travel, and finishes the recording medium in the opening section when the conveyance section temporarily stops the traveling recording medium.
 12. The apparatus of claim 11, wherein the finishing section is a staple unit to staple a plurality of the recording medium.
 13. The apparatus of claim 11, wherein the finishing section is a punch unit to form a hole in the recording medium.
 14. The apparatus of claim 11, wherein the finishing section is a staple unit to staple a plurality of the recording medium and a punch unit to form a hole in the recording medium.
 15. The apparatus of claim 11, wherein the finishing section finishes the traveling recording medium a plurality of numbers of times, and the conveyance section temporarily stops the traveling recording medium each time the finishing section finishes the medium.
 16. The apparatus of claim 11, further comprising an alignment section which moves the recording medium in a direction perpendicular to the paper discharge direction and laterally aligns a side of the recording medium parallel to the paper discharge direction, and in which an opening section side wall of the finishing section is a lateral alignment reference surface of the recording medium.
 17. The apparatus of claim 11, wherein the conveyance section includes a conveyance belt and a clip which is disposed on the conveyance belt and clips the recording medium.
 18. An image forming apparatus comprising: an image forming section to form an image on a recording medium; a conveyance section to convey the recording medium supplied from the image forming section in a paper discharge direction; and a sheet finishing section which includes an opening section protruding to a conveyance path from a side, parallel to the paper discharge direction, of the conveyance path of the recording medium in the conveyance section and finishes the recording medium traveling in the opening section.
 19. The apparatus of claim 18, wherein the sheet finishing section is arranged in a hollow barrel formed in a main body of the image forming section.
 20. A sheet finishing method, comprising: conveying a recording medium supplied from an image forming section in a paper discharge direction; stopping the recording medium temporarily while the recording medium is conveyed in the paper discharge direction; finishing a side of the recording medium parallel to the paper discharge direction when the recording medium is temporarily stopped; and restarting conveyance of the recording medium in the paper discharge direction after the finishing is performed.
 21. The method of claim 20, wherein a process is repeated a plurality of numbers of times, in which the recording medium is stopped temporarily while the recording medium is conveyed in the paper discharge direction, the finishing is performed when the recording medium is temporarily stopped, and the conveyance is restarted after the finishing is finished. 